The city council of any city of the first class or any county of the first class may by ordinance or resolution adopt the food stamp program. Upon adoption of the program the city or county shall appropriate money and shall pay, quarterly from city or county funds, the amounts certified to the city or county as being the obligations to the State Department of Public Welfare¹ for thirty per cent of the amount expended by the department for administration of the food stamp program for the county or city during the fiscal year 1965-1966, for forty per cent of the amount expended during the fiscal year 1966-1967 and for fifty per cent of the amount expended during the fiscal year 1967-1968 and thereafter.